Automobile over-bulkhead air intake system

ABSTRACT

An automobile air intake system is provided that channels air from outside the automobile engine compartment to the engine. The automobile air intake system according to an embodiment of the invention includes an intake enclosure coupled to a bulkhead across the front of the engine compartment. The automobile grille, radiator, and a front portion of the hood in front of the bulkhead form a flow channel to an intake port of the intake enclosure. Aspects of the invention include a screen extending from the bulkhead to the grille for inhibiting the flow of water and particles through the flow channel. Other aspects provide an alternative air path for channeling air from the engine compartment to the intake enclosure.

This application is a continuation of U.S. application Ser. No.11/754,942 filed on May 29, 2007, which is a continuation of U.S.application Ser. No. 10/887,851 filed on Jul. 12, 2004, now issued asU.S. Pat. No. 7,237,635, both expressly incorporated herein byreference.

TECHNICAL FIELD

This invention relates generally to an automobile air intake system.More particularly, the invention relates to an automobile over-bulkheadair intake system and a method for drawing air into a combustion engine.

BACKGROUND

Air intake systems provide necessary air to internal combustion enginesto aid in the combustion process. Conventional intake systems eitherdraw air from inside the engine compartment, or they draw air fromoutside the vehicle via an exterior intake port. Systems designed wherethe air is drawn from inside the engine compartment commonly suffer adrawback of drawing in warmer and less dense air than exterior air. Thisreduces the efficiency of the engine compared with the use of coolerexterior air. A solution to address the shortcoming of these systems isto draw in cooler exterior air. However, systems designed where the airis drawn in via an exterior intake port commonly suffer a drawback ofdrawing in air that includes water or particles, which can block theengine intake, inhibit airflow, or damage the engine. Solutions havebeen proposed to address the shortcomings of these exterior intake portsystems.

U.S. Pat. No. 5,564,513 to Wible et al. discloses an exterior air intakesystem for an internal combustion engine that includes an intake portdisposed under the vehicle hood in front of the radiator. The intakeport includes a filter for removing solid particulates from the intakeair and for separating water from the air. The intake port, however,requires a large space forward of the radiator under the hood of thevehicle, which is difficult to fit within the compact enginecompartments of contemporary vehicles. Further, due to the filter'sproximity to the exterior opening of the port, the filter may have apropensity to clog quickly to inhibit airflow and may require frequentchanging.

U.S. Pat. No. 6,510,832 issued to Maurer et al. discloses an exteriorair intake system for an internal combustion engine that is aimed atavoiding water intake by providing a main air inlet to exterior air, anauxiliary air inlet, a moisture sensor, and an electric valve to closethe main air inlet. When moisture is sensed in the main inlet, theelectric valve closes the main inlet and air is drawn from the enginecompartment into the auxiliary air inlet. The Maurer system, however,requires pneumatic or electro-pneumatic drives and an electricalmoisture sensor. These complicated elements may be subject to anincreased chance of failure.

U.S. Pat. No. 5,022,479 to Kiser et al. discloses a rectangular channelformed in the vehicle hood that includes a forward ambient air inlet anda rear air outlet. The channel includes a series of baffles to capturemoisture from air flowing therethrough. A sealing sleeve is provided tobridge between the channel and the engine air cleaner. The Kiser systemhas drawbacks in that it occupies a large amount of hood space andrelies upon a special sleeve design to connect with the air cleanersystem.

U.S. Pat. No. 4,971,172 to Hoffman et al. discloses air ducts formed inthe hood of a truck to eliminate water and heavier particles from theair stream. The intake pathway includes vertical ducts with drainholesto permit the drainage of water collected in the pathway. The intakepathways occupy a large amount of hood space and create a long conduitto the intake system, which inhibits efficient airflow.

Accordingly, a need exists for an improved air intake system. Inaddition, a need exists for a method of efficiently obtaining coolexterior air for an internal combustion engine having low moistureand/or particulate content.

SUMMARY

In order to overcome drawbacks of the prior art and/or provide analternate arrangement, aspects of the present invention provide anautomobile air intake system for providing air from outside the enginecompartment to the engine. The automobile air intake system according toan embodiment of the invention includes an intake enclosure coupled to abulkhead across the front of the engine compartment. The automobilegrille, radiator, and a front portion of the hood in front of thebulkhead form an airflow channel to an intake port of the intakeenclosure. Aspects of the invention include a screen extending from thebulkhead to the grille for inhibiting the flow of water and particlesthrough the flow channel and for forming a transverse intake path. Otheraspects provide an alternative air path for channeling air from theengine compartment to the intake enclosure.

Aspects of the present invention further provide an automobile airintake system for providing air from the engine compartment to theautomobile engine via an intake path through the hood. The intake paththrough the hood may be an alternate path for providing air to theengine when a primary path is at least partially obstructed. Accordingto an embodiment of the invention, the automobile air intake systemincludes an intake enclosure and a hood having a passageway forproviding air from the within the engine compartment to the intakeenclosure. Other features and advantages of various aspects of theinvention will become apparent with reference to the following detaileddescription and figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in detail in the following descriptionof preferred embodiments with reference to the following figureswherein:

FIG. 1 is a front perspective view of an automobile air intake systemaccording to an embodiment of the invention;

FIG. 2 is an enlarged front right perspective view of Detail 2 of FIG.1;

FIG. 3 is a front left perspective view of a portion of the automobileair intake system of FIG. 1 shown with the hood in an open position;

FIG. 4 is a rear perspective view of a portion of the automobile airintake system of FIG. 1 as viewed from within the engine compartmentwith the hood in an open position;

FIGS. 5 and 6 are top and side views respectively of the air intakeenclosure of FIG. 1;

FIG. 7 is a front view of a portion of the automobile air intake systemof FIG. 1 shown with the hood in a closed position;

FIG. 8 is a partial cross-sectional view taken through line 8-8 of FIG.7;

FIG. 9 is a front perspective view of an automobile air intake systemaccording to another embodiment of the invention;

FIG. 10 is a partial cross-sectional view taken through line 10-10 ofFIG. 9;

FIG. 11 is a perspective view of Detail 11 of FIG. 9 showing the hoodframe with the hood skin removed;

FIG. 12 is a perspective view of a portion of the automobile air intakesystem of FIG. 9 showing the air flow into the air intake enclosure;

FIG. 13 is perspective view of a portion of an automobile air intakesystem similar to FIG. 11 according to a further embodiment of theinvention showing the hood frame with the hood skin removed; and

FIG. 14 is a perspective view of a portion of the automobile air intakesystem of FIG. 13 showing the airflow into the air intake enclosure.

DETAILED DESCRIPTION

Referring The various aspects of the invention may be embodied invarious forms. The following description shows by way of illustrationvarious embodiments in which aspects of the invention may be practiced.It is to be understood that other embodiments may be utilized andstructural and functional modifications may be made without departingfrom the scope of the present invention. Referring now to FIGS. 1-8, anautomobile air intake system 10 is shown according to an embodiment ofthe invention as part of an automobile 12. As shown, automobile airintake system 10 generally includes an air intake enclosure 14 and aflow path 16 (see FIG. 8) to intake enclosure 14, which is generallyformed by grille openings 19 through a grille 18, a radiator 20, and afront portion 22 of hood 24 disposed at the front portion of automobile12. Automobile air intake system 10 provides cooler air from outside theengine compartment to the automobile engine (not shown) while deterringthe ingress of particles and water contained in the air from being drawninto air intake enclosure 14.

As shown in FIGS. 1-4, automobile 12 includes a frame 26 formingboundaries of an engine compartment 28. Disposed across the front ofengine compartment 28 is a transverse frame element commonly referred toas the bulkhead 30. Bulkhead 30 is generally a structural frame member,such as a U-shaped steel bar, that traverses a front region of theengine compartment along a top region of the compartment. Air intakeenclosure 14 is disposed above bulkhead 30 and can be attached directlyto the bulkhead, to a bulkhead cover 56, and/or to other structures viahardware such as bolts and/or other common connectors. As shown in FIG.4, air intake enclosure 14 provides an air passageway to air filter unit34, which further channels filtered air to the automobile engine (notshown).

Referring specifically to FIGS. 5 and 6, air intake enclosure 14generally includes walls 37, which together form a channel 44 forchanneling air along airflow path 45 to air filter unit 34. At a frontportion of intake enclosure 14, walls 37 may include a base 36 opposedby a top 38, and a pair of opposing sidewalls 40 and 42. Front portionsof base 36, top 38 and sidewalls 40 and 42 form an intake port 46generally facing toward the front of automobile 12. Intake port 46 ispreferably oblique from base 36 and/or from the cross-section of airflowpath 45 to provide an opening that is larger than the cross-section ofchannel 44 perpendicular to airflow path 45 at intake port 46. Forinstance, as shown in FIG. 6, intake port 46 may form an acute angle.alpha. with airflow path 45 and/or base 36 at point 45 a through intakeport 46. Acute angle .alpha. is preferably between about 5 degrees and85 degrees, and is more preferably between about 30 degrees and 60degrees. Even more preferably, acute angle .alpha. is about 45 degrees,which provides an intake port 46 having a larger area than thecross-section of channel 44 perpendicular to airflow path 45. Asdiscussed further below, this reduces the airflow velocity at intakeport 46 to reduce the possibility of drawing in water and particles inthe air. As shown, base 36, top 38 and sidewalls 40 and 42 curvetogether along airflow path 45 to form circular tube 48 extending towardair filter unit 34.

The cross-sectional area of channel 44 perpendicular to airflow path 45preferably tapers down from a relatively large cross-sectional area atpoint 45 a, as created by width W and the channel height at that point,to a smaller cross-sectional area based on the diameter D of tube 48leading to air filter unit 34. Preferably, the cross-sectional area ofchannel 44 perpendicular to airflow path 45 at point 45 a has aneffective diameter that is 10 percent or more than the effectivediameter of the cross-sectional area of the channel along tube 48perpendicular to airflow path 45 at point 45 d. This provides a lowerair velocity at intake port 46 than along tube 48 for a given volumetricflow rate through channel 44. For example, the effective diameter atpoint 45 a may be about 99 cm² and the effective diameter at point 45 dmay be about 88 cm². As discussed later in concert with FIG. 8, lessparticulate and/or water content is drawn into air intake enclosure 14at lower air velocities through intake port 46, such as permitted viathe relatively large cross-sectional area at point 45 a, than would bedrawn in with higher air velocities at the intake port, such as if thevelocity at point 45 d due to its smaller cross-sectional existed atpoint 45 a. Air intake enclosure 14 is preferably a molded plastic unitas is known in the art, which is airtight, generally lightweight, androbust, yet inexpensive to manufacture; however, it can be formed viaother known manufacturing technologies, such as from an assembly ofmetal or plastic components.

Air intake enclosure 14 is shaped and adapted to extend over radiator20, which is preferably aligned underneath a high point or apex 50 ofbase 36 of air intake enclosure 14 (see FIG. 8). Thus, as shown in FIG.6, base 36 and airflow path 45 at point 45 b are inclined as they extendfrom intake port 46 to base apex 50. This encourages particles, objects,water, etc, to exit channel 44 via intake port 46, which may have beendrawn into or fallen into channel 44. Stated another way, base apex 50forms a gravity bias at the front of intake enclosure 14 to dischargeparticles, moisture, or objects out of the front of intake enclosure 14through intake port 46. To further encourage such items to leave channel44, base 36 forms a step 52 disposed within intake port 46. In the eventobjects such as tools fall through intake port 46 into channel 44 whenthe hood is in an open configuration, step 52 encourages these objectsto exit channel 44 via intake port 46.

Placing radiator 20 below base apex 50 permits the radiator to bedisposed behind bulkhead 20. As discussed later along with FIG. 8,radiator 20 is preferably disposed rearward of bulkhead 30, rather thanaligned with or in front of bulkhead 30, which is most common inconventional vehicles. The rearward offset of radiator 20 from bulkhead20 can reduce turbulence along flow path 16, reduce the absorption ofheat from radiator 20 by intake air, and provide space for intake port46 on top of bulkhead 30 by allowing bulkhead 30 to be lower than thetop of radiator 20.

As shown in FIG. 6, base 36, channel 44 and airflow path 45 arepreferably angled downward extending from base apex 50 toward air filterunit 34 along tube 48, as shown by points 45 c and 45 d. A bottom point54 may exist along tube 48 prior to connecting with air filter unit 34(see FIG. 4), which allows any objects or moisture drawn into channel 44to collect for withdrawal in concert with air filter changes and/or toact as a fluid trap. Optionally, a drain hole (not shown) may be formedin tube 48 at bottom point 54 to permit the drainage of any moisturedrawn into channel 44.

As shown in FIGS. 2, 3 and 8, a bulkhead cover 56 is disposed on top ofbulkhead 30 and is preferably mounted substantially flat on top ofbulkhead 30. Bulkhead cover 56 extends forward from the top of bulkhead30 to the top of grille 18 and includes a plurality of holes 58 formedtherethrough, which form a mesh or screen 60. Screen 60 forms an airpermeable barrier across flow path 16 for inhibiting moisture dropletsand relatively large particles from entering air intake enclosure 14without significantly affecting the flow rate of the incoming air.Screen 60 should have holes that are small enough to screen out mostdebris, but not too small to significantly restrict airflow. Forexample, screen 60 may include holes having an area of about 140 squaremillimeters, which will prevent the ingress of most debris and permitgood airflow therethrough. The moisture droplets and particles may befrom water or particles splashed or thrown on the front of automobile12, as well as from moisture or particles carried by intake air. Screen60 provides an initial deflection of these items, which can prevent theintake system from being clogged or requiring premature replacement ofthe air filter (not shown).

Preferably, screen 60 extends between bulkhead 30 and grille 18 at anangle from horizontal to encourage any particles or moisture collectedon screen 60 to travel downward and fall from screen 60. Morepreferably, as shown in FIG. 8, screen 60 is angled downward frombulkhead cover 56 to grille 18 at a downward angle γ from the top ofbulkhead cover 56, which encourages particles or moisture collected onscreen 60 to travel downward away from radiator 20 and avoid being drawnthrough the radiator. Downward angle γ is preferably between about 15degrees and 85 degrees, and more preferably between about 30 degrees and60 degrees. Even more preferably, angle γ is about 45 degrees. Downwardangle γ in these ranges enables screen 60 to deflect items splashed orthrown toward the flow path 16 due to the small angle of incidence atwhich such items are likely to encounter screen 60 when angled downwardat angle γ.

Referring specifically to FIG. 8, flow path 16 is illustrated withrespect to various components of air intake system 10. As shown,radiator 20 is disposed rearward in the vehicle of bulkhead 30 beneathbase apex 50. In conventional vehicles, the radiator 20 is superimposedbeneath the bulkhead 30 relatively close to grille 18. Offsettingradiator 20 entirely rearward of bulkhead 30 provides a relatively largefrontal space 62 compared with placing radiator 20 directly belowbulkhead 30. Since radiator 20 is not superimposed beneath bulkhead 30,it provides flexibility in design to place bulkhead 30 lower in theengine compartment than conventional arrangements, such as generallyeven with or entirely below the top of radiator 20. (This also providesspace for intake port 46 without significantly increasing the height ofhood 24, if at all). Large frontal space 62 provides a pocket of airthat is less turbulent than conventional arrangements, which reduces themixing of intake air with warmer air proximate radiator 20. As such,cooler exterior air, which is denser and more efficient for combustionthan warmer air, can be provided to air intake enclosure 14 andultimately to the automobile engine (not shown). Frontal space 62 alsoprovides a location for water disposed in the area of the intake path todrain down away from intake port 46.

As shown in FIG. 8, air is drawn into air intake enclosure 14 along flowpath 16. The air flows in from the front of vehicle 12 through gaps 19in grille 18. When vehicle 12 is being operated under average drivingconditions, air is forced into frontal space 62 in a generally rearwarddirection along portion 16 a of flow path 16 due to forward motion ofvehicle 12. Radiator 20 and/or other components of vehicle 12 partiallydam the air, which causes the air pressure to increase in frontal space62. This encourages the air to turn about 90 degrees or more from itsrearward path at portion 16 b to flow upward along portion 16 c. Assuch, air flowing through grille 18 turns such that it flows at an angleδ at portion 16 b from its entry path to flow upward and forward alongportion 16 c through screen 60. Preferably, angle δ is about 15 degreesto 85 degrees, and more preferably is about 45 degrees. Channelingintake air to turn angle δ encourages moisture droplets and particlessuspended in the air along portion 16 a to continue rearward rather thanbeing drawn along the relatively sharp turn of 16 b along flow path 16.

The engine intake system provides vacuum via intake port 46 of airintake enclosure 14 to further encourage air from frontal space 62 toturn along portion. 16 b and flow upward along portion 16 c. Vacuum fromthe intake system may be the primary moving force to encourage air tomove along flow path 16 when the vehicle is not moving or is movingrearward. Once intake air is drawn in through screen 60 along portion 16c, the inside of hood frame 172 at a forward portion of hood 24 channelsthe air to turn it rearward at portion 16 d and to channel it towardintake port 46 along portion 16 e. The rearward turn at portion 16 dfurther encourages remaining moisture droplets or particles to drop outof the air, such as by collecting on the inside of hood frame 172. Thus,flow path 16 may be a serpentine path that is generally S-shaped in thevertical plane, which encourages suspended particles and moisturedroplets drawn through grille 18 to continue rearward toward theradiator based on their greater mass and momentum in comparison with theair. Flow path 16 further encourages remaining particles and moisturedroplets to collect along screen 60 or the inside of hood frame 172.Thus, the amount of moisture and particulate drawn into the air intakesystem is reduced compared with non-winding intake paths.

This arrangement provides advantages over simpler winding intake paths,as the large rearward momentum of the particles and moisture dropletsentering grille 18 at normal vehicle driving speeds encourages theirseparation from the air. To reduce particulate and moisture contentfurther, screen 60 is disposed to capture particles and liquid dropletsthat may continue along portion 16 c of flow path 16 or that may splashupward along the air path. The serpentine flow path 16, which isgenerally S-shaped as viewed in the vertical plane, can eliminate alarge amount of moisture droplets and particles from intake air, whichis enhanced by screen 60.

In addition to the vertical channeling of intake air as illustrated bythe general S-shape shown in FIG. 8, flow path 16 also channels a largeportion of intake air horizontally to further reduce the amount ofparticulate and moisture droplets further. As shown in FIG. 1, screen 60generally extends across grille 18 a distance S that is much wider thanthe width W of intake port 46. Thus, as shown in cross-section in FIG.8, a generally horizontal bulkhead channel 64 is formed between the topof grill 18, bulkhead cover 56, screen 60, and the inside of hood frame172. After intake air is drawn through screen 60, depending on itslateral relation to intake port 46, it may be channeled laterally alongbulkhead channel 64. Within bulkhead channel 64, the intake air ischanneled laterally to turn an angle of about ninety degrees forchanneling it toward air intake port 46.

Seals 66 and 68 are preferably disposed fore and aft of bulkhead channel64, which may be attached to the underside of hood frame 172, to providea generally airtight flow path 16 extending laterally toward intake port46. Seals 66 and 68 are preferably made from compressible materials,such as rubber or foam, which can provide tight seals between the insideof hood frame 172 and grille 18, the top of intake air enclosure 14, andbulkhead cover 56. Tight seals enhance the effectiveness of air intakesystem 10 by ensuring the majority of intake air travels via airflowpath 16 into intake port 46. Other seals, such as tongue-and-grooveconfigurations between the inside 172 of hood 24 and bulkhead cover 56or other structures, are also contemplated for generally sealingbulkhead channel 64. Vacuum from the engine provides low air pressureinside air intake enclosure 14, which encourages intake air to travelalong bulkhead channel 64 into intake port 46. Higher pressure withinintake space 62 during forward movement of vehicle 12 further encouragesintake air to travel along bulkhead channel 64 into intake port 46 dueto the width of grille 18 and screen 60 compared with intake port 46.Thus, although a portion of intake air may travel generally verticallyup through screen 60 directly into intake port 46, a significant portionof intake air may travel laterally within bulkhead channel 64 alongbulkhead cover 56 from portions of screen 60 that are not disposeddirectly in front of intake port 46. Such lateral channeling of much ofthe intake air further encourages moisture droplets and particles todrop out of the intake air.

Various aspects of air intake system 10 combine together to reduce thequantity of moisture droplets and particulate in intake air. Reducingthe amount of moisture droplets and particles in intake air increasesthe life of the air filter disposed in air filter unit 34, providescleaner air to the intake system and engine, and provides cooler outsideair for combustion, which can greatly increase the efficiency of theengine (not shown). Turns 16 b and 16 d of the vertical portion of flowpath 16, combined with the lateral channeling of air through bulkheadchannel 64 portion of flow path 16 and the low air velocity along flowpath 16, encourages many particles and moisture droplets to exit theintake air prior to entry through intake port 46. Due to greater lengthof bulkhead channel 64 compared with the width of intake port 46, thevelocity of air being drawn through screen 60 can be lower than thevelocity of air entering through intake port 46. As discussed abovealong with FIGS. 5 and 6, the intake velocity at intake port 46 is keptrelatively low compared with the velocity along tube 48, which evenfurther reduces the ingress of moisture and particles. These aspectscombine together to greatly reduce the ingress of moisture and particlesinto air intake system 10.

In addition to providing cooler and cleaner air during normal drivingcondition provided by the aforementioned aspects of intake air system10, which can be practiced individually or together, air intake system10 further reduces the possibility of drawing moisture and particlesinto the intake system during more extreme driving conditions. Theplacement of intake port 46 as high as possible against the inside ofhood 24 reduces the likelihood of water entering the intake systemduring extreme driving conditions, such as through heavy rain storms orhigh-standing water. As long as air can enter flow path 16, such as viathe top portion of grille 18, cooler exterior intake air can be providedto the intake system that has reduced moisture and particulate content.Even during these extremely wet conditions, the vertical and lateralchanneling of air along airflow path 16, the low intake air flow ratethrough airflow path 16, and the screening of the air through screen 60reduce the likelihood of water droplets being drawn into air intakesystem 10.

Referring now to FIGS. 9-12 along with FIGS. 1-8, an automobile airintake system 110 according to another embodiment of the invention isshown. Intake system 110 provides an alternate intake path forconducting air contained within engine compartment 28 to intake port 46in the event a primary intake path to exterior air is unavailable orpartially blocked. Automobile air intake system 110 generally includesthe aspects and preferences of air intake system 10 discussed above,except regarding the alternate intake path. Although air intake system110 generally includes the aspects and preferences of intake system 10,aspects of air intake system 110 related to an alternate intake path maybe practiced apart from the aspects and preferences of air intake system10. Further, the alternate intake path aspects of system 110 may bepracticed as a primary or sole intake path for providing air from anengine compartment to an engine.

In addition to the features disclosed along with embodiment 10,automobile intake system 110 generally includes an air intake pathwithin hood 24 that extends between engine compartment 28 and bulkheadchannel 64. As shown in FIG. 10, hood 24 includes an outer skin 170 thatis generally uninterrupted, and a hood frame 172 spaced apart from andattached to the underside of hood skin 170. Hood frame 172 forms aplurality of intake orifices 174 generally disposed in the centralregion of the hood 24 for drawing in air from within engine compartment28. Gaps between hood skin 170 and hood frame 172 form one or more airpassageways 176 for conducting air from within engine compartment 28 viaintake orifices 174 to an exit port 178, which feeds into bulkheadchannel 64. As shown, exit port 178 may be a latch hole through hoodframe 172 used to engage a latch 179 when hood 24 is in the closedposition. Passageways 176 provide an alternate intake path from insidethe engine compartment to bulkhead channel 64, which leads to intakeport 46. Thus, in the event the primary airflow path 16 providingexterior air to intake port 46 is partially or fully blocked, air withinengine compartment 28 may be channeled into the engine (not shown) tokeep it running. This can be a great advantage for unexpected emergencyconditions, such driving into deep flood waters.

FIG. 11 is a top perspective view of hood frame 172 with hood skin 170removed to show the passageways 176 within hood 24 for conducting airfrom engine compartment 28 via intake orifices 174 to exit port 178.Intake orifices 174 include large orifices 174 a, which can serve thedual purpose of reducing the weight of hood 24 by eliminating elementsof hood frame 172 and providing large airflow into air passageways 176,and small orifices 174 b. The small orifices can be strategically formedwithin hood frame 172 to provide air intake advantages. For instance,small orifices 174 b may be placed nearer to exit port 178 than largerorifices 174 a to improve flow through hood passageways 176 withoutsignificantly affecting the strength of hood frame 172. In comparisonwith smaller orifices 174 b, the placement of large orifices 174 a maybe more significantly governed by hood frame strength considerations. Inanother example, small orifices 174 b may be placed in desirable intakepositions within engine compartment 28, such as at high points in hood24 or in positions away from concentrations of engine heat.

Hood frame 172 shown in FIG. 11 includes a bulge 182 that, on itsopposite side, forms an intake enclosure cavity 180 on the underside ofthe hood frame 172. As shown in FIG. 8, cavity 180 receives a topportion of intake enclosure 14 and provides a space 184 in front ofintake port 46, which permits intake air entering intake port 46 to havea relatively slow velocity compared with the velocity along tube 48 ofintake enclosure 14. As shown in FIG. 12, air exiting exit port 178enters bulkhead channel 64 and is channeled into intake port 46 viacavity 180.

Passageways 176 shown in FIG. 11 are preferably used to provide air tothe automobile engine on condition the primary path, such as flow path16, is at least partially blocked. For example, suppose a vehiclesuddenly encounters floodwaters 186 with a water level at a depth 186 aup to the height of grille 18 or greater as shown in FIG. 10. The waterblocks airflow at portion 16 a of flow path 16 from providing air tobulkhead channel 64 and thereby to intake port 46. As such, theautomobile engine (not shown) on an automobile without intake system 110may stall and/or draw in water, and the vehicle driver may becomestranded. With an intake system such as automobile intake system 110,intake port 46 may draw air from inside engine compartment 28 viapassageways 176, exit port 178 and bulkhead channel 64 to thereby permitcontinued operation of the engine (not shown).

Because intake orifices 174 are disposed at the top of enginecompartment 28 within hood 24, the air drawn in is not proximate to thewater 188 disposed within engine compartment 28. Further, becauseradiator 20, grille 18, and other front portions of the automobile actas dam while the automobile moves forward, the level 188 a of waterwithin the engine compartment should be lower than the level of water186 b in front of radiator 20 or the level of water 186 a in front ofthe vehicle. Thus, the automobile engine (not shown) can continue tooperate through the high water levels by drawing air through airpassageways 176, exit port 178 and bulkhead channel 64 into intake port46.

In addition to providing an alternate path for intake air, automobileintake system 110 provides winding passageways to inhibit the intake ofmoisture droplets and particles into intake enclosure 14. The largesizes of the intake orifices 174 in hood frame 172 and the passageways176 within the hood allow the air to be withdrawn from the enginecompartment at a relatively slow velocity compared with the velocitythrough intake enclosure 14. The inside of hood 24 along passageways 176may act like baffles to condense and capture moisture contained withinthe intake air. Further, the flow channel through exit orifice 178 andbulkhead channel 64 encourages moisture and particles to be removed fromthe intake air in a manner similar to flow path 16 by turning the air asit leaves exit orifice 178 and enters bulkhead channel 64.

During normal operation of automobile 12 in which flow path 16 is notobscured, little if any air will be drawn through passageways 172 fromengine compartment 24. This is because high pressure in frontal space 62during forward vehicle motion drives air into bulkhead channel, whichwill not favor and may likely discourage airflow into bulkhead channel64 from exit orifice 178. When vehicle 12 is not moving, the path ofleast resistance will likely be through airflow path 16 rather than viaexit orifice 178, because the cross-sectional flow area through exitorifice 178 is small compared with airflow path 16. As such, passageways176 require a larger pressure differential to draw air therethrough thanairflow path 16. During normal operating conditions, air is readilyavailable via the comparably large intake area of flow path 16. However,when flow path 16 becomes partially or fully blocked, the vacuum drawfrom the engine (not shown) via intake enclosure 14 increases at exitorifice 178 due to restricted air intake, which increases the pressuredifferential between engine compartment 28 and bulkhead channel 64 tothereby draw air through air passageways 172 and exit orifice 174.

Referring now to FIGS. 13 and 14, an automotive intake system 210according to a further embodiment of the invention is shown. Automotiveintake system generally includes the aspects and preferences ofautomotive intake system 210, except as relating a second exit orificewithin hood skin 172. As shown in FIG. 13, hood frame 172 forms a secondexit orifice 192 through bulge 180 and intake enclosure cavity 180 thatextends into space 184 in front of intake port 46. This additional portprovides increased airflow to intake enclosure 14 from enginecompartment 24 on condition flow path 16 becomes partially or fullyblocked. Passageways 190 conduct air from the engine compartment 24 tosecond exit orifice 192 in concert with passageways 176 for conductingair to exit orifice 178. Intake air exits second exit orifice 192 viapath 183 shown in FIG. 14 to enter intake port 46. Optionally, one ormore valves (not shown), such as spring biased valves, may be providedat exit orifices 178 and 192 to prevent inflow from the alternativepassageways during normal operating conditions. When the vacuum drawwithin bulkhead channel 64 increases due to limited air supply, theoptional valves (not shown) may open to provide access to thealternative passageways 172 and 190.

Automobile air intake systems 10, 110 and 210 illustrate various aspectsof an automotive air intake system according to the present invention.These systems provide cool exterior air to the engine during normaldriving conditions, which may have fewer particles and lower moisturecontent. In addition, aspects of these systems can reduce thepossibility of drawing moisture and particles into the intake systemduring more extreme driving conditions, such as heavy rain or high waterconditions. The aspects of the present invention disclosed in theseembodiments can be practiced individually or together. For instance,aspects related to airflow path 16 may be practiced without practicingaspects related to the configuration of air intake enclosure 14. Inanother example, the alternate intake path aspects of system 110 may bepracticed as a primary or sole intake path for providing air from anengine compartment to an engine.

While the present invention has been described in connection with theillustrated embodiments, it will be appreciated and understood thatmodifications may be made without departing from the true spirit andscope of the invention. In particular, the invention applies to manydifferent types of vehicles and intake configurations.

1. A vehicle air intake system, comprising: a bulkhead disposed across aforward portion of an engine compartment; a grille disposed forward ofthe bulkhead; a hood disposed over the engine compartment; an intakeenclosure coupled to the bulkhead, the intake enclosure having an intakeport, and wherein the bulkhead, the grille and the hood create aserpentine airflow path to the intake port; a screen extending from thebulkhead to the grille transverse to the serpentine airflow path; andwherein the screen is angled downward from the bulkhead to the grille.2. The intake system of claim 1, wherein the screen is angled downwardfrom horizontal at an angle between 15 degrees and 85 degrees.
 3. Theintake system of claim 2, wherein the screen is angled downward fromhorizontal at an angle between 40 and 50 degrees.
 4. The intake systemof claim 1, wherein the intake enclosure forms an intake channel forchanneling air from the intake port at a first end of the enclosure toan air filter coupled with a second end, the intake channel beinginclined as it extends from the intake port, the intake channel inclinesfrom the intake port to an apex and declines from the apex downstreamalong the intake channel, and the grille, the bulkhead, and the hooddefine a serpentine airflow path to the intake port.
 5. The intakesystem of claim 4, wherein the intake enclosure includes a plurality ofwalls and a base forming the intake channel, end portions of the wallsand base forming the intake port as an entryway to the intake channel,the end portions of the intake walls being oblique from the base at theintake port at an angle between 15 degrees and 85 degrees.
 6. The intakesystem of claim 5, wherein the angle is between 30 and 60 degrees. 7.The intake system of claim 5, wherein the intake port generally facestoward the front of the vehicle and the intake walls are angled towardthe rear of the vehicle.
 8. The intake system of claim 4, furthercomprising a seal disposed between the hood and the grille.
 9. Theintake system of claim 4, wherein the intake enclosure forms an intakechannel for channeling air from the intake port at a first end of theenclosure to an air filter coupled to a second end, the intake channelhaving a first cross-sectional area proximate the intake port thattapers to a second cross-sectional area at a point downstream of theintake port, the first cross-sectional area having an effective diameterabout 10% or more greater than the second cross-sectional area forreducing the air velocity at the intake port.
 10. The intake system ofclaim 9, wherein the first cross-sectional area effective diameter isabout 99 cm² and the second cross-sectional area effective diameter isabout 88 cm².
 11. The intake system of claim 4, further comprising aradiator disposed within the engine compartment, wherein the apex isdisposed rearward of the bulkhead and the radiator is substantiallyaligned beneath the apex.
 12. The intake system of claim 11, wherein theintake enclosure is stepped at a bottom of the channel near the intakeport in a plane intersecting the apex.
 13. The intake system of claim 4,wherein the hood includes an outer hood skin and an inner hood frame,the hood skin and the hood frame forming an alternate intake passagewaytherebetween for placing the engine compartment and the intake port influid communication.
 14. The intake system of claim 13, furtherincluding a latch for locking the hood in a closed configuration,wherein the hood frame forms an exit port proximate the hood latch whenthe hood is in a closed configuration.
 15. The intake system of claim13, wherein the hood frame forms an exit port proximate the intakeenclosure intake port when the hood is in a closed configuration. 16.The intake system of claim 1 wherein the intake enclosure includes: abase; and a plurality of walls, the walls and the base forming anairflow channel having a first end and a second end with an intake portdefined at the first end; wherein the base is inclined along the channelfrom the intake port to an apex, and declines from the apex toward thesecond end, and the base has a step adjacent the intake port forencouraging objects to travel out of the intake channel.
 17. The intakesystem of claim 16, wherein the base and walls form a first channelportion at the first end having a first cross-sectional area and asecond channel portion spaced apart from the first cross-sectional areatoward the second end having a second cross-sectional area, the firstcross-sectional area having an effective diameter about ten percent ormore larger than an effective diameter of the second cross-sectionalarea.
 18. The intake system of claim 16, wherein the intake port isformed in a plane angled between 5 degrees and 85 degrees from the base.19. The intake system of claim 1 wherein the intake enclosure includes:a base; and a plurality of walls, the walls and the base forming anairflow channel having a first end and a second end with an intake portat the first end; wherein the airflow channel includes a bulge betweenthe first and second ends at a high point between the first and secondends, and the intake port is formed in a plane angled between about 5degrees and about 85 degrees from the base, and the base has a stepadjacent the intake port for encouraging objects to travel out of theintake channel.
 20. The air intake enclosure of claim 19, wherein thebase and walls form a first channel portion at the first end having afirst cross-sectional area and a second channel portion having a secondcross-sectional area spaced apart from the first cross-sectional area,the first cross-sectional area having an effective diameter about tenpercent or more larger than an effective diameter of the secondcross-sectional area.
 21. A vehicle air intake system, comprising: abulkhead disposed across a forward portion of an engine compartment; agrille disposed forward of the bulkhead; a hood disposed over the enginecompartment; an intake enclosure coupled to the bulkhead, the intakeenclosure having an intake port, and wherein the bulkhead, the grilleand the hood create a serpentine airflow path to the intake port; ascreen extending from the bulkhead to the grille transverse to theserpentine airflow path; and wherein the hood includes an outer hoodskin and an inner hood frame, the hood skin and the hood frame formingan alternate intake passageway therebetween for placing the enginecompartment and the intake port in fluid communication.
 22. The intakesystem of claim 21, further including a latch for locking the hood in aclosed configuration, wherein the hood frame forms an exit portproximate the hood latch when the hood is in a closed configuration. 23.The intake system of claim 21, wherein the hood frame forms an exit portproximate the intake enclosure intake port when the hood is in a closedconfiguration.
 24. An air intake system for a vehicle comprising: abulkhead disposed across a front portion of an engine compartment; agrille disposed forward of the bulkhead; a hood disposed over the enginecompartment; an intake enclosure coupled to the bulkhead, the intakeenclosure having an intake port; a seal disposed between the hood andthe intake enclosure; wherein the grille, the bulkhead, and the hoodcreate a serpentine airflow path to the intake port; and wherein thehood includes an outer hood skin and an inner hood frame, the hood skinand the hood frame forming an alternate intake passageway therebetweenfor placing the engine compartment and the intake port in fluidcommunication.
 25. The intake system of claim 24, further including alatch for locking the hood in a closed configuration, wherein the hoodframe forms an exit port proximate the hood latch when the hood is in aclosed configuration.
 26. The intake system of claim 24, wherein thehood frame forms an exit port proximate the intake enclosure intake portwhen the hood is in a closed configuration.